$4/1 Knox Coupon = Overage at Publix! This post may contain affiliate links. Please see the full disclosure policy here. Posted on January 25, 2010 Written by Mary Leave a Comment Did you get a $4/1 Knox coupon in your 1/24 Red Plum insert? The coupon states $4 off ANY Knox product..meaning you can purchase Knox Gelatine at Publix which is priced around $1.39 and get $2.61 OVERAGE (if your store allows)!! Thanks, Iheartpublix!!